Envelope



' June 19, 1934.

E. F. AHLQUlsT. 1,963,639

ENVELOPE l `Filed nec. 21, 1931 2 sheets-sheet 2 INVEA/T HG. 6 F76. 7:06E/vf: f: 4m. Qu/.sr

562112, @LQ M Patented June 19, 1934 UNITED STATES PATENT oFF1cEQ,

c 2 Claims.

Y This invention relates to new and useful improvements in envelopes,and an object of the invention is to provide an envelope having meansembodied in the construction thereof whereby, 5 when the envelope hasonce been sealed, it cannot beV opened and resealed without defacing ormutilating it so that the receiver may note, at a glance, that theenvelope has been tampered with by an unauthorized` person. f

prising a body portion having an opening and a ilap adapted to form aclosure for said opening, said ap being gummed whereby it may be securedto the body portion of the envelope to seal said opening, and a portionof the gummed portion of said flap being treated in such a manner as tothe fibers, or weaken the material break down thereof, whereby the flapcannot be opened without defacing or mutilating it.

A vvfurther object is to provide an envelope comprising a flap adaptedto provide a closure for the usual opening thereof, and a portion of theflap being treated in such a manner as to weaken a portion of thematerial thereof, as for example, by subjecting it to high pressure, orby closely perforating al portion of the nap, or by subjecting a portionof the nap to heat, or to the action of chemicals, whereby the fibersare weakened to the extent that the ilap cannot be opened, after it hasonce been secured to the body of the envelope, without tearing orotherwise mutilating it.

Other objects of the invention will appear from the followingdescription and accompanying drawings and will be pointed out in theannexed (claims.

In the accompanying drawings there has been disclosed a structuredesigned to carry out the various objects of the invention, but it is tobe understood that the invention is not confined A to the exact featuresshown, as various changes may be made within the scope of the claimswhich follow.

In the drawings:

Figure l is a view showing an envelope with Vthe invention embodied inthe construction thereof and showing the flap in open unsealed position;

Figure 2 is a view showing the iiap sealed and the portions of the iiapwhich have been treated in accordance with the invention;

Figure 3 is a view similar to Figure 2 showing an instrument insertedunder the flap to open it, and also showing the treated portion of theap torn or mutilated by the instrument;

Figure 4 is a view showing an envelope having a A further object is toprovide an envelope com-- portion of its flap treated substantially thefull length thereof;

Figure 5 is a similar view showing an insitrument inserted under theweakened flap and indicating how it is mutilated thereby;

Figure 6 is a view vshowing a portion ot lan envelope having its flapprovided with at plurality of closely disposed perforations for thepurpose of weakening it; and

Figure l is a viewshowing a, portion oi". :nsealed Gi envelope with aseparate seal secured to the flap thereof. v l y In the selectedembodiment of the invention here shown, for purposes of disclosure,there is illustrated in Figure 1, an envelope comprising 'IO end flaps 2and 3 and a bottom flap 4 folded, one over therother, and suitablysecured together to provide the body of the envelope. The broken line 5indicates where the top flap 6 is folded to close and seal the envelope,as shown in Figures (57. 2 and 3. It will be noted that the upper edgesof the end flaps extend above the fold line 5 so that when the top ilap6 is folded against the envelope body and sealed, it will be impossiblefor a person to insert an instrument into the S0... interior of theenvelope body rwithout'damaging the walls thereof or breaking the sealofk the envelope.

An important feature of this invention resides in treating portions ofthe flap 6 in such a man- 85 ner that when once it has been sealed, itcannot be opened and resealed without being so marked that the recipientof the letter or envelope may readily note that it has been tamperedwith.

To thus treat the flap 6, I have shown in Figures l to 3, circularportionsl-Jl and 8 thereof which have been treated in a manner to causethe fibers of the material to become weakened so that when the flap issecured to the body portion of the envelope, as shown in Figures 2 95,;and 3, by the gum or adhesive usually provided upon the flap, it cannotbe reopened without tearing or mutilating the flap. This may beaccomplished in various ways as, for example, by` subjecting the treatedportions of the flapr to 1(10, heat, or high pressure, or to the actionof certain acids or chemicals.

Preferably, only portions of the gummed portion of the flap are treatedas shown in Figures 1 and 3, so that when the ilap is sealed, the 105.'weakened portions thereof will not be of sufficient magnitude to weakenthe seal. By treatingY portions of the flap as shown' in Figures 2 and3, when a letter opener or other suitable in- Gila strument is insertedunder the sealed flap 6, 110,"

and it contacts with one of the treated portions '7 or 8 of the iiap,these portions will be destroyed as shown at the left hand side ofFigure 3, because of the frail and weakened condition of said treatedportions, and because they are secured to the envelope body in the samemanner as the flap.

By thus treating portions of the iap, the usual metallic seals or locksnow commonly used on various types of commercial. envelopes may bedispensed with. Metallic locks and seals add considerably to themanufacturing cost of the envelopes, and are usually more or less bulkyand are therefore objectionable. By treating portions of the flap asdisclosed in this invention, the envelope when sealed is renderedsubstantially as secure as if metallic locks or seals Were used for thereason that the flap, when once secured to the body portion, cannot beopened and resealed without leaving a mark which may be quickly noted bythe recipient of the envelope. Also, by treating the flaps as hereindisclosed, very little is added to the manufacturing cost, therebyproviding such an article embodying all of the advantages of themetallic seals or locks now usedand, at the same time, considerablyreducing the cost of the article and facilitating the operation ofclosing and sealing the envelope.

In the manufacture of the envelopes, I have found that by applying heatto the portions 7-7 and 8 of the flap by means of suitable dies, theiiap may be treated without materially adding to the cost ofmanufacture, and also when using heat, suitable information may beimpressed in the treated portions of the envelope such, for example, asadvertising matter and a return address.

In Figures 4 and 5, I have illustrated an envelope body 9 having a nap10, the lower marginal edge portion 11 of which is treated as abovedescribed so that when an attempt is made to open the envelope with aninstrument 12, after once the flap 10 has been sealed, the flap willbecome damaged or defaced to the extent that it may be quickly noted bythe recipient, as clearly illustrated in Figure 5.

Figure 6 shows another method of treating a portion of the iiap toweaken it by providing therein a series of closely disposed perforations13. When the ap is thus treated, it cannot readily be opened Withouttearing the perforated portion of the flap so that if an attempt to openthe sealed envelope is made by an unauthorized person, it may be quicklynoted.

In some cases, it may be found desirable, in lieu of treating portionsof the iiap as above described, to aflix an individual seal 14 to thesealed envelope iiap, as shown in Figure 7, which seal has beenpreviously treated toA render it weak and frail, so that the flap cannotbe opened Without tearing or destroying said seal.

I claim as my invention: l

l. An envelope comprising a body portion having an opening therein and agummed flap for closing said opening, and portions of the gumznedportion of said flap 'being heat-treated to break down and weaken thefibers thereof so that the flap cannot be opened without tearing ormutilating said weakened portions.

2. An envelope comprising a body portion having an opening therein and agummed flap for closing said opening, and a portion of said flapadjacent its free edge and extending substantially the entire lengththereof being subjected to the action or" heat, thereby to break downand weaken the bers thereof whereby the iiap cannot be opened withouttearing or mutilating said weakened portion.

EUGENE F. AHLQUIST.

